1 Lewis and Clark went on one of greatest adventures in the 1800s. They got the chance to journey through lands that white men knew very little about. The trip wasn't always fun and exciting. There were many parts that were hard for the men, but they never gave up.2 Before they started on the journey, Lewis and Clark looked at maps of the west. These were maps that President Thomas Jefferson had. Many of the maps showed what people thought were in the west. "Thought" is a very important word here. Very few people had ever been to these places. Many geographers just filled in this part of the map with what they had heard from legends. They also used a little bit of wishful thinking.3 Thomas Jefferson hoped to find a river that would go all the way to the Pacific. Because many people wanted this, it was drawn in on the maps. This is where the wishful thinking comes in. That river did not exist. People drew it in on maps anyway. They hoped that someone would be able to find this river. The Lewis and Clark journey proved that it did not exist.